A.Jackson Avro Aircraft since 1908 (Putnam)

Avro 527 and Avro 528

While the Avro 523 Pike was under construction in the Manchester works, A. V. Roe and Co. Ltd. were also building a modified, two seat version of the Avro 504G for the Royal Flying Corps. It was fitted with a 150 h.p. Sunbeam engine and a standard central skid undercarriage but retained the fixed fin normally fitted only to R.N.A.S. machines. The mainplanes were standard Avro 504K units of 36 ft. span with which it was designated Avro 527, and a second version with a span of 42 ft. was also considered under the designation Avro 527A. The machine was not a success, the rate of climb was poor, and as on the Avro 519 the radiator and twin exhaust stacks seriously obstructed the pilot's forward view. Type number Avro 528 was given to a similar but more powerful aeroplane ordered by the Admiralty and fitted with a 225 h.p. Sunbeam engine. This machine followed the Avro 523A Pike through the works in July-August 1916 but no other information concerning it or the Avro 527 has survived.

F.Manson British Bomber Since 1914 (Putnam)

Avro Type 528

Little is known of the Avro Type 528, a single-engine, three-bay biplane whose construction at Miles Platting is said to have followed immediately after the Type 523A Pike in the late summer of 1916. It was covered by Avro Works No 2350 and only one example was built; however, it has been suggested that two serial numbers, A316 and A317, allocated to A V Roe by the Admiralty, may have been allocated to this type, and that a second aircraft was planned, but cancelled. Powered by a 225hp Sunbeam driving a four-blade propeller, the Type 528 was designed as a bomber, its bombs being carried in two nacelles on the lower wing, inboard of the inner pair of interplane struts. Bearing in mind that the aircraft was in fact larger than the twin-engine Pike with 150hp Green engines, the bomb load must have been relatively small, and in no way comparable with that of the successful Short Type 184. The Avro aircraft also featured folding wings. The Sunbeam engine installation, though itself neatly cowled, was compromised by the attachment of two large vertical radiators on either side of the front fuselage immediately forward of the pilot's cockpit, a location that must have severely restricted his view, further limited by the bomb containers on the lower wings. Few details have survived of the aircraft, and the date of first flight - probably during the autumn of 1916 - is not known.

H.King Armament of British Aircraft (Putnam)

527. This Sunbeam-engined 504 development of 1915/16 was a last attempt to develop the type as a fighter. The pilot was not armed, but the gunner had a Lewis gun on a pillar mounting, apparently operating conjointly with a guide-ring.

528. A mystery aeroplane, which seems to have existed (1916), and which may well have had bomb nacelles mounted on the lower wing. If this fact could be substantiated the 528 might be considered as the Wellesley of its time.

W.Green, G.Swanborough The Complete Book of Fighters

AVRO 527

The final two-seat fighter derivative of the basic Avro 504 design, the Avro 527 was built for the RFC and flown for the first time early in 1916 with a 150 hp Sunbeam Nubian eight-cylinder water-cooled engine. The mainplanes, undercarriage and tail assembly were basically similar to those of the Avro 504, but the fuselage differed markedly from that of the earlier aircraft. Proposed armament consisted of a single free-mounted 0.303-in (7,7-mm) Lewis gun in the rear cockpit. The Avro 527 displayed a poor climb rate and the pilot’s forward view was seriously impaired by the twin exhaust stacks of the Nubian engine. Only one prototype was completed, and development was discontinued during the course of 1916, a version with a longer-span wing, the 527A, being discarded at the same time.